This small 16th-century church in Athens is almost entirely surrounded by a modern building.

The ruins of an abandoned medieval city where the last Byzantine emperor was crowned.

This remarkable cave was discovered after a shepherd watched bees enter and exit through a small fissure.

This mystical orb covered in strange symbols is thought to have been used in ancient Greek magical rituals.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

An ancient octagonal weather station named for the eight Greek gods of wind.

This legendary city has been a tourist attraction for centuries.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

Legends surround an ancient tree trunk riddled with nails for good luck.

Baroque celebration of the end of the Great Plague of Vienna.

Op-art architecture designed for happiness.

Legend says if you stick your thumb in the hole and it gets wet, your wish will be granted.

1513 Turkish world map, full of European state secrets and snarky commentary.

Learn to drink tea like an Estonian at this museum.

A medieval setting reimagined into a unique art alley.

This 13th century Gothic brick castle is the largest in the world by surface area.

Naturally formed rock city in Poland.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

A Baroque mansion with ties to legendary magicians and alchemists.

A cheeky reminder about the value of art dangles above one of Olomouc's busiest streets.

An unusual bronze bus shelter is actually an art installation commenting on the city's history with the Nazi party.

Tiny communists hammer away on the Olomouc Astronomical Clock.

Tall columns of volcanic basalt make up this improbable-seeming rock formation.

The sanctuary holds what was once believed to be the saint's incorruptible tongue.